Contact portion of semiconductor device, and thin film transistor array panel for display device including the contact portion

ABSTRACT

A method for manufacturing a semiconductor device including forming a first wire on a substrate, forming a lower film on the first wire, forming a photosensitive pattern on the lower film using a photosensitive material, forming contact holes for exposing the first wire by etching the lower film using the photosensitive film as an etching mas, removing part of the photosensitive film pattern by an ashing process to expose a borderline of the lower film defining the contact holes and forming second wire connected to the firs wire via the contact holes.

The present application is a divisional application of U.S. patentapplication Ser. No. 10/466,299 filed on Aug. 1, 2003, which is anapplication filed under 35 U.S.C. §371 and hereby claims the benefit ofInternational Patent Application No. PCT/KR02/01878 filed Oct. 8, 2002designating the United States of America. The above-listed U.S. and PCTapplications are related to the present application and are hereinincorporated by reference in their entirety.

BACKGROUND OF THE INVENTION

(a) Field of the Invention

The present invention relates to a contact portion of semiconductordevice and a method for manufacturing the same, and a thin filmtransistor array panel for display device including the contact portionand the method for manufacturing the same.

(b) Description of the Related Art

In general, it is preferable that, as a semiconductor device is moreintegrated, an area of the device is optimized and a wiring thereof ismade of multi-layers. In this case, preferably, an interlayer insulatingfilm is made of material with a low dielectric constant in order tominimize an interference of signals transferred through the wiring, andthe wiring transferring the same signals has to be connectedelectrically by forming a contact hole in an insulating film. However,if an under-cut is generated on the contact portion on forming thecontact hole by etching the insulating film, a step coverage of thecontact portion becomes bad. This causes a problem that a profile of thewiring formed on the insulating film becomes bad or the wiring in thecontact portion is disconnected.

In the meanwhile, a liquid crystal display (LCD) is one of flat paneldisplay devices which are used most widely, and it is a display devicethat comprises two substrates on which electrodes are formed and aliquid crystal layer interposed therebetween, and that applying theelectrodes makes the liquid crystal molecules in the liquid crystallayer rearranged, thereby adjusting amount of the light transmitted.

The mainly used LCDs are those that electrodes are formed on twosubstrates respectively and have a thin film transistor switchingvoltages applied to the electrodes.

In general, on the substrate where a thin film transistor is formed,wire including gate lines transmitting scanning signals and data linestransmitting data signals, and a gate pad and a data pad applied withthe scanning signals and data lines from external devices to transmitthe gate lines and the data lines respectively, are formed, and pixelelectrodes electrically connected with the thin film transistor areformed on pixel areas defined by crossing the gate lines and the datalines.

Here, it is preferable that an aperture rate of the pixel is sure to beobtained in order to improve display features of the LCDs. For this, thewire and the pixel electrodes are made to overlap with each other, aninsulating film made of organic material with a low dielectric constantis formed therebetween in order to minimize interferences of signalstransmitted through the wire.

This method for manufacturing the thin film transistor array substratefor display device requires a process that exposes a pad for receivingsignals from external devices or a process that exposes wire in order tobe connected with each other. However, when a lower film is etched toform a contact hole thereon by using an insulating film having thecontact hole as a mask, the lower film beneath the insulating film isseverely under-cutted, and hence the step coverage of the contactportion becomes bad. This causes problems that the other upper filmsformed later become bad or the wire of the upper films are disconnectedon the contact portion. To solve these problems, it is preferable thatsidewalls of the contact holes in the contact portion are made to bestep-shaped, however, since the organic insulating film must bepatterned several times by a photo etching for this, it has a problemsthat its manufacturing process becomes complex.

In the meanwhile, a seal line attaching two substrates around the LCDpanel and sealing liquid crystal material posed therebetween is formed,and a poor contact is generated if this seal line is formed on theorganic insulating film.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a contact portion ofsemiconductor device and a method for manufacturing the same, and a thinfilm transistor array panel and a method for manufacturing the sameincluding the same capable of improving the profile of the contactportion.

In addition, another object of the present invention is to simplify amethod for manufacturing a thin film transistor array panel.

Furthermore, another object of the present invention is to provide athin film transistor array panel capable of removing the poor contact.

To solve these problems, in the present invention, when an organicinsulating film having contact hole is formed, the periphery of thecontact hole is formed thinner than the other portions. Next, theexposed lower film is etched using the organic insulating film as anetching mask to form contact hole thereon, and thereafter, the thinorganic insulating film is removed by an ashing process to expose thelower film through the contact hole of the organic insulating film.Here, in case under-cut is left under the lower film, a process, whichthe lower film is etched using the organic insulating film as an etchingmask, may be added.

More in detail, in the contact portion of the semiconductor device andthe method for manufacturing the same according to the presentinvention, first, a first wiring is formed on the substrate, and thelower film covering the first wiring is formed. Next, a photosensitivefilm pattern is formed on the lower film using a photosensitive organicmaterial, and the lower film is etched using the photosensitive filmpattern as an etching mask, thereby forming the contact hole forexposing the first wiring. Then, part of the photosensitive film patternis removed by an ashing process to expose borderline of the lower filmdefining the contact hole, and then a second wiring connected to thefirst wiring via the contact hole is formed.

The lower film may be formed of an insulating film made of SiNx or SiOx,or may be formed of a conducting film made of conducting material.

In addition, the lower film may be formed of a first insulating layerand a second insulating layer, in this case, it is preferable that,after exposing the borderline of the lower film, the second insulatingfilm not blocked by the photosensitive film pattern is etched to exposethe borderline of the first insulating film, wherein the secondinsulating film is formed of a low dielectric insulating film which hasa low dielectric constant less than 4.0 and is formed by a chemicalvapor deposition.

Here, it is preferable that the photosensitive film pattern around thecontact hole is formed thinner than that in the otherportions.

The contact portion of the semiconductor device and the manufacturingmethod thereof according to this present invention are equallyapplicable to a thin film transistor for liquid crystal display and amanufacturing method thereof.

First, in a manufacturing method of a thin film transistor array panelfor liquid crystal display, gate wire, which include a gate line, a gateelectrode connected to the gate line and a gate pad connected to one endof the gate line to transmit a scanning signal from a external device tothe gate line, are formed on an insulating substrate. Next, afterforming a gate insulating film and a semiconductor layer, data wire,which include a data line crossing with the gate line, a sourceelectrode connected to the data line and adjacent to the gate electrode,a drain electrode placed opposite to the source electrode in relation tothe gate electrode and a data pad connected to one end of the data lineto transmit an image signal from an external device to the data line,are formed. Next, after depositing a insulating film and forming aphotosensitive organic insulating film pattern, the insulating film isetched using the photosensitive organic insulating film pattern as anetching mask to form a first contact hole for exposing the gate pad orthe data pad. Then, after exposing the borderline of the insulating filmin the first contact hole by the ashing process, an assistant padconnected to the gate pad or the data pad via the first contact hole isformed.

It is preferable that the organic insulating pattern around the firstcontact hole is formed thinner than that in the other portions.

The insulating film may formed of a first insulating film and a secondinsulating film, in this case, it is preferable that after exposing theborderline of the insulating film, the second insulating film notblocked by the organic insulating film pattern, and then the organicinsulating film is removed. Here, the second insulating film is a lowdielectric insulating film which has a low dielectric constant less than4.0 and is formed by a chemical vapor deposition.

Here, it is preferable that the organic insulating film has a secondcontact hole for exposing the drain electrode and a pixel electrodeelectrically connected to the drain electrode via the second contacthole is formed on the same layer as the assistant pad.

It is preferable that the second contact hole is formed with the firstcontact hole and the organic insulating film pattern around the secondcontact hole is formed thinner than that in the otherportions.

The data wire and the semiconductor layer may be formed by a photoetching process using photosensitive patterns whose thickness is partlydifferent.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a to FIG. 1 e are cross-sectional views showing a method formanufacturing a contact portion of a semiconductor device by a processorder according to a first embodiment of the present invention.

FIG. 2 a to FIG. 2 d are cross-sectional views showing a method formanufacturing a contact portion of a semiconductor device by a processorder according to a second embodiment of the present invention.

FIG. 3 is a thin film transistor array panel for liquid crystal displayaccording to the first embodiment.

FIG. 4 is a cross-sectional view taken along IV-IV′ of the thin filmtransistor panel shown in FIG. 3.

FIGS. 5 a, 6 a, 7 a and 8 a are arrangement diagrams of the thin filmtransistor panel in the mid-process of manufacturing the thin filmtransistor panel for liquid crystal display according to the firstembodiment of the present invention.

FIG. 6 b is a cross-sectional view taken along VIb-VIb′ shown in FIG. 6a, and shows next step of FIG. 5 b.

FIG. 7 b is a cross-sectional view taken along VIIb-VIIb′ shown in FIG.7 a, and shows next step of FIG. 6 b.

FIG. 8 b is a cross-sectional view taken along shown in FIG. 8 a, andshows next step of FIG. 7 b.

FIG. 8 c is a cross-sectional view showing an area where a seal linewill be formed on the thin film transistor array panel for liquidcrystal display according to the first embodiment.

FIG. 9 is a cross-sectional view taken along shown in FIG. 8 b, andshows next step of FIG. 8 b.

FIG. 10 a is a cross-sectional view taken along shown in FIG. 8 a, andshows next step of FIG. 9 b.

FIG. 10 b is a cross-sectional view showing next step of FIG. 8 c.

FIG. 11 is an arrangement view of a thin film transistor panel forliquid crystal display according to a second embodiment.

FIG. 12 and FIG. 13 are cross-sectional views taken along X II-X II′ andX III-X III′ of the thin film transistor shown in FIG. 11.

FIG. 14 a is an arrangement view of thin film transistor in a firststep, manufactured according to the second embodiment of the presentinvention.

FIG. 14 b and FIG. 14 c are cross-sectional views taken along X IVb-XIVb′ and X IVc-X IVc′ shown in FIG. 14 a, respectively.

FIG. 15 a and FIG. 15 b are cross-sectional views taken along X VIb-XIVb′ and X IVc-X IVc′ shown in FIG. 14 a, respectively, and shows nextstep of FIG. 14 b and FIG. 14 c.

FIG. 16 a is an arrangement view of thin film transistor of next step ofFIG. 15 a and FIG. 15 b.

FIG. 16 b and FIG. 16 c are cross-sectional views taken along X VIb-XVIb′ and X VIc-X VIc′ shown in FIG. 16 a, respectively.

FIGS. 17 a, 18 a, 19 a and FIGS. 17 b, 18 b, 19 b are cross-sectionalviews taken along X VIb-X VIb′ and X VIc-X VIc′ and shown in FIG. 16,respectively, and show next step of FIG. 16 b and FIG. 16 c by a processorder.

FIG. 20 a is an arrangement view of thin film transistor in next step ofFIG. 19 a and FIG. 19 b.

FIG. 20 b and FIG. 20 c are cross-sectional views taken along X X b-X Xb′, and shown in FIG. 20 a, respectively.

FIG. 21 a and FIG. 21 b are cross-sectional views taken along X X b-X Xb′ and X X c-X X c′ and shown in FIG. 20 a, respectively, and show nextstep of FIGS. 20 b and 20 c by a process order.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A contact portion of semiconductor device and a method for manufacturingthe same, and a thin film transistor array panel and a method formanufacturing the same including the contact portion of semiconductordevice and the method for manufacturing the same according toembodiments of the present invention will be described in detain withreference to accompanying drawings so that those skilled in the artpractice easily.

First, a contact portion and a method for manufacturing the same will bedescribed according to an embodiment of the present invention.

In general, as a semiconductor device is more integrated, it ispreferable that an area of thereof is made to be optimized or its wiringis formed of multi-layers for the purpose of assisting a pad connectedto signal lines for receiving signals from external devices. Asemiconductor device according to an embodiment of the present inventionincludes an interlayer insulating film with a low dielectric constantfor the purpose of minimizing interferences of signals transferredthrough wire, and an organic film made of an organic material that asmoothing feature is excellent. Here, a contact hole needs to be formedon the insulating layer in order to electrically connect the wirebetween layers with each other, and when the interlayer insulating filmis etched to form the contact hole, a manufacturing method according toan embodiment of the present invention makes a periphery of the contacthole of the organic insulating film thinner than the other portionsthereof for the purpose of removing the under-cut generated in thecontact portion. Next, a lower film is etched using the organicinsulating film as a etching mask, and then an ashing process isperformed to remove the thin insulating film, thereby exposing the lowerfilm.

FIG. 1 a to FIG. 1 e are cross-sectional views showing a method formanufacturing a contact portion of a semiconductor device by a processorder according to a first embodiment of the present invention, and FIG.2 a to FIG. 2 d are cross-sectional views showing a method formanufacturing a contact portion of a semiconductor device by a processorder according to a second embodiment of the present invention.

In a manufacturing method of a contact portion of a semiconductor deviceaccording to the first embodiment of the present invention, as shown inFIG. 1 a, first, a lower insulating film 310 made of SiNx or SiOx isdeposited on a substrate 100 where a first wiring 200 is formed, andthen, as an upper insulating film, an organic insulating film 320 with alow dielectric constant and made of a photosensitive organic material iscoated thereon, thereby forming a interlayer insulating films 300.

Next, as shown in FIG. 1 b, a transmittance area is formed on a portioncorresponding to a contact hole 330 in order to forming the contact hole330 for exposing the first wiring 200, and for the purpose of adjustinga light transmittance, around the transmittance area, a slit or alattice type pattern is mainly formed, or the organic insulating filmpattern, which is exposed and developed using a mask with asemi-transmittance area where a semi-transparent film is formed to havethe contact hole 330 for exposing the lower insulating film 310 on thefirst wiring 200, is formed. In this regard, by exposing and developingthe organic insulating film 320 using the mask with a semi-transmittancearea, the organic insulating film 320 around the opening portion is leftto be thinner than that in the other portions. This will be described indetail in a manufacturing method of a thin film transistor panel forliquid crystal display according to a fourth embodiment of the presentinvention which manufactures the thin film transistor for liquid crystaldisplay using four masks. It is preferable that the thickness of theorganic insulating film 320 around the contact hole 30 is not more than2,000 Å in consideration of the thickness removed in the ashing processthereafter.

Then, as shown in FIG. 1 c, the lower insulating film 310 exposedthrough the contact hole 330 is etched to expose the first wiring 200.Here, since reaction of an etching gas is performed isotropically in theprocess of etching even using a dry etching, let alone a wet etching,the lower insulating film 310 is etched to the organic insulating filmpattern 320, and hence an under-cut is generated.

Next, as shown in FIG. 1 d, an ashing process is performed to removepart of the organic insulating film pattern 320 which is aphotosensitive film. The organic insulating film, which the periphery ofthe contact hole 330 is formed thinner than the other portions, iscompletely removed to make the border line of the lower insulating filmbe exposed.

Then, as shown in FIG. 1 e, a conducting material is deposited on theorganic insulating film pattern 320, and patterned by a photo etchingprocess using a mask, thereby forming a second wiring 400 electricallyconnected to the first wiring 200 via the contact hole 330.

In the contact portion of the semiconductor device and the manufacturingthereof according to the first embodiment of the present invention, whenthe interlayer insulating film is made of an organic material and thecontact hole for exposing the first wiring 200 is formed, by forming thesidewall of the organic insulating film 320 step-shaped and performingthe ashing process after etching the lower insulating film 310, theunder-cut structure generated under the organic insulating film of thecontact portion is removed. This can prevent the second wiring fromdisconnecting with the first wiring, and improve the profile of thesecond wiring 400 in the contact portion smooth.

Although the lower insulating film 310 under the organic insulating film320 has been described as an example, this is equally applicable to casethat a lower film of the organic insulating film 320 is also aconducting film. That is, as in the method the present invention formanufacturing of the contact portion, in case the conducting film underthe organic insulating film is etched, when the conducting film isetched to the lower part of the organic insulating film to form anunder-cut on the contact portion, by forming the periphery of thecontact hole thinner and removing this by the ashing process to exposethe conducting film on the contact portion, the under-cut thereon can beremoved.

In the meanwhile, in a contact hole of a semiconductor device and amanufacturing thereof according to a second embodiment of the presentinvention, as shown in FIG. 2 a, when an interlayer insulating film 300is made of a dual layer including a lower insulating film 310 and anupper lower insulating film 320, and the insulating film 300 ispatterned using the organic insulating film 320 (See FIG. 1 b) as aphotosensitive pattern of an etching mask to form the contact hole forexposing a first wiring 200, the lower insulating film 310 is etched tothe lower part of the upper insulating film to be able to generate anunder-cut. Also, in this case, as shown in FIG. 2 a, part of thephotosensitive film pattern 500 around the contact hole 330 is formedthinner than that in the otherportions.

Next, part of the photosensitive film pattern 500 around the contacthole 330 formed thinner than that in the otherportions is removed byperforming an ashing process. Here, it is preferable that an etchingcondition has an etching selectivity of the upper insulating film 320and the lower insulating film 310.

Next, as shown in FIG. 2 d, by removing the photosensitive film pattern500, depositing a conducting material on the upper insulating film 320,and patterning it by a photolithography process using a mask, a secondwiring 400 electrically connected to the first wiring 200 is formed.

In the contact portion of the semiconductor device and the manufacturingthereof according to the second embodiment of the present invention,when the interlayer insulating film is made of an organic material andthe contact hole exposing the first wiring 200 is formed, by forming thephotosensitive film defining the contact hole step-shaped and performingthe ashing process after etching the lower insulating film 330 to removea part of the photosensitive film, and the upper insulating film isetched again using the photosensitive mask as a mask, thereby removingthe under-cut structure generated in the contact portion. This canprevent the second wiring 400 from disconnecting with the first wiring200, and improve the profile of the second wiring 400 in the contactportion smooth.

In the meanwhile, the contact portion of the semiconductor device andthe manufacturing method thereof can be also applicable to a thin filmtransistor array substrate for liquid crystal display and amanufacturing method thereof. Here, it will be described that thecontact portion of the semiconductor and the manufacturing methodthereof according to the first embodiment of the present invention isapplied to a thin film transistor for liquid crystal display and amanufacturing method thereof according to the first embodiment of thepresent invention, and that the contact portion of the semiconductor andthe manufacturing method thereof according to the second embodiment ofthe present invention is applied to a thin film transistor for liquidcrystal display and a manufacturing method thereof according to thesecond embodiment of the present invention.

First, a structure of a thin film transistor panel for liquid crystaldisplay according to a first embodiment of the present invention will bedescribed in detail with reference to FIG. 3 and FIG. 4.

FIG. 3 shows a thin film transistor panel for liquid crystal displayaccording to a first embodiment of the present invention, and FIG. 4 isa cross-sectional view taken along the IV-IV′ of the thin filmtransistor shown in FIG. 3.

Gate wire including aluminum-based metal material having a lowresistance are disposed on an insulating substrate 10. The gate wireinclude gate lines 22 extending in a horizontal direction, gate pads 24connected to one end of the gate lines 22 to transmit gate signals froman external device to the gate lines, and gate electrodes 26 of the thinfilm transistor connected to the gate lines 22.

The gate wire 22, 24 and 26 are preferably formed of aluminum-basedsingle layer, however, they may be formed of more than two layers. Incase of forming more than two layers, it is preferable that one layer isformed of a material with a low resistance and the other layers areformed of chromium-based or molybdenum-based materials that areexcellent in a contact characteristic with other materials such as ITO,IZO or the substrate.

A gate insulating film 30 made of SiNx, etc., covers the gate wire 22,24 and 26 on the substrate 10, and has a contact hole 74 for exposingthe gate pad 24 with a passivation layer 70 formed later.

A semiconductor layer made of semiconductor such as amorphous silicon,etc., is formed on the gate insulating layer of the gate electrode 24,and, ohmic contact layers 55 and 56 made of material such as n⁺hydrogenated amorphous silicon doped with high-concentrated silicide orn-type impurity, are formed on the semiconductor layer 40, each of whichis formed divided into two parts as seen in the center of gate pad 26.

Data wire 62, 64, 65 and 66 made of metals, for example, Al or Al alloy,Mo or MoW alloy, Cr, Ta, etc., or of conductor, are formed on the ohmiccontact layers 55 and 56 and the gate insulating film 30. The data wireinclude data lines disposed in a vertical direction, crossing with thegate lines 22 to define the pixels, source electrodes 62 which arebranches of the data lines and extend to upper side of the ohmic contactlayer 55, data pads 68 connected to one end of the data lines 62 andreceiving image signals from an external device, and drain electrodes 66separated from the source electrodes and formed on the ohmic contactlayer 56 disposed opposite to source electrodes 65 in relation to thegate electrodes 26. In the meanwhile, the data wire may include aconductor pattern for storage capacitor which overlaps the gate lines 22and has a purpose of securing a storage capacity.

The data wire 62, 64, 65, 66 and 68 may be formed of single layer madeof Al or Al alloy too, and formed of more than dual layers. In case ofbeing formed of dual layers, it is preferable that one layer is formedof material with a low resistance and the other layers are formed ofmaterial whose the contact characteristic is excellent. As such anexample, there are Cr/Al (or Al alloy) or Al/Mo, and in this regards, Crfilm has a function to prevent Al film or Al alloy film from beingdispersed into Si layers 40, 55 and 56, which also has a function as acontact portion for securing contact characteristics between the datawire 62, 64, 65, 66 and 68 and pixel electrodes formed later.

On the data wire 62, 64, 65, 66 and 68 and the semiconductor layer 40not blocked by those, the passivation layer 70 made of SiNx, and anorganic insulating film made of acril-based photosensitive organicmaterial having a smoothing characteristic and a low dielectricconstant, are formed. On the passivation layer 70, the conductor patternfor storage capacitor 64, the drain electrodes 66 and the contact holes72, 76 and 78 for exposing the data pads 68 are formed respectively, andalso, the contact hole 74 for exposing the gate pads 24 with the gateinsulating film 30 is formed. Here, the borderline of the organicinsulating film in the contact holes 72 and 76 is formed on thepassivation film 70 to expose the borderline of the passivation film 70or the gate insulating film 30, and hence the sidewalls defining thecontact holes 72 and 76 become step-shaped. In addition, it ispreferable that the organic insulating film 75 is removed from the padportion where the gate pads and the data pads are formed, and thecontact hole 74 for exposing the gate pad 24 is formed larger than thegate pad 24.

On the organic insulating film 75, pixel wire, which include pixelelectrodes 82 connected to the drain electrodes 66 via the contact hole76 and located in the pixels, and assistant gate pads 84 and assistantdata pads 88 each connected to the gate pads 24 and the data pads 68 viathe contact holes 74 and 78, and are made of ITO (indium tin oxide) orIZO (indium zinc oxide) which is a transparent conducting material, areformed. In this regard, as described above, in the contact portion, thesidewall of the passivation film 70 or the organic insulating film 75, alower insulating film has a step-shaped and has no under-cut structure,and therefore this can prevent the pixel electrodes, the assistant gatepads 84 and the assistant data pads 88 from being disconnected. Here,since the organic insulating film 75 is removed from the pad portion,the assistant gate pads 84 and the assistant data pads 88 are formedonly to the upper side of the passivation film 70. The reason is thatthe organic insulating film 75 is very poor of adhesive strength,chemical-resisting quality, hardness, mechanical intensity, stress,etc., compared with a passivation film made of SiNx. Therefore, in casethat the organic insulating film 75 exists in the pad portion, when adriving integrated circuit is directly mounted on a thin film transistorfor liquid crystal display using COG (chip on glass) manner or a filmwhere a driving integrated circuit is packed by TCP or COF manner isattached thereto, an adhesive strength of the pad portion is poor and,in turn, this cause a poor adhesion. In addition, when rework isrequired to improve the poor adhesion, an anisotropy conducting filmshould be removed from the pad portion after the driving integratedcircuit or the film is detached therefrom, and here, if the organicinsulating film remains behind, this causes a problem of a surfacedamage of the pad portion or an ITO film peeling-off between the organicinsulating film and the assistant films 84 and 88. Thus, completelyremoving the organic insulating film from the pad portion can improvethe adhesive strength between the pad and the driving integrated circuitor the film, and can practice the rework very easily.

As shown in FIGS. 3 and 4, the pixel electrodes overlaps the gate lines22 to form storage capacitors, and here, when the storage capacities aredeficient, independent wires for storage capacities separated from thegate wire 22, 24 and 26 may be added to the same layer as the gate wire22, 24 and 26.

Then, the method for manufacturing a thin film transistor for liquidcrystal display according to the first embodiment of the presentinvention will be described in detail with reference to FIGS. 3 and 4,and FIG. 5 a to FIG. 10.

First, as shown in FIGS. 5 a and 5 b, on a substrate 10, a conductingmaterial whose contact characteristic is excellent or which hasresistance such as Al or Al alloy, and Ag or Ag alloy, is deposited andpatterned to form gate wire including gate lines 22, gate electrodes 26and gate pads 24.

Next, as shown in FIGS. 6 a and 6 b, three-layer film, a gate insulatingfilm 30, a semiconductor layer 40 made of an amorphous silicon and adoped amorphous silicon layer 50, is deposited successively, and thesemiconductor layer 40 and the doped amorphous silicon layer 50 arepatterned by a patterning process using a mask, thereby forming thesemiconductor layer 40 and the ohmic contact layer 50 on the gateinsulating film 30 disposed opposite to the gate electrode 24. In thisregard, as shown in FIGS. 6 a and 6 b, the semiconductor layer 40 andthe ohmic contact layer 50 are formed along the data lines formed later.

Next, as shown in FIGS. 7 a and 7 b, a conducting material such as Cr,Mo or Mo alloy, Al or Al alloy, or Ag or Ag alloy is deposited, andthen, patterned by a photo etching using a mask to form data wireincluding data lines 62 crossing with the gate lines, source electrodes65 connected to the data lines 62 to extend to upper side of the gateelectrodes 26, data pads 68 connected to one end of the data lines 62,drain electrodes 66 separated from the source electrodes 65 and disposedopposite thereto, and conductor patterns for storage capacitors.

Next, the amorphous silicon layer pattern 50 not blocked by the datawire 62, 64, 65, 66 and 68 is etched to be divided into two partscentering around the gate electrode 26, and simultaneously thesemiconductor layer 40 interposed between the doped amorphous siliconlayers 55 and 56 is exposed. Then, it is preferable to practice anoxygen plasma in order to stabilize a surface of the exposedsemiconductor 40.

Next, as shown in FIGS. 8 a and 8 b, the passivation layer 70 made ofSiNx is deposited no more than 2,000 Å thick, preferably, 1,000 Å thick,and the organic insulating film 75 made of a organic insulating materialwith a photosensitivity is formed in a range of 2˜4 μm thick thereon,and, first, only the organic insulating film 75 is exposed and developedby a photo process using a mask to form contact holes 72, 74, 76 and 78on the conductor pattern for the storage capacitor 64, the gate pad 24,the drain electrode 66 and the data pad 68, respectively. A pattern ofslit type or a lattice type, or a semi-transmittance area made of asemi-transparent film is formed so that a light transmittance aroundtransmittance area of the mask is reduced, and the organic insulatingfilm 75 around the pad portion where several pads 24 and 68 are formedor the contact holes 74 and 78 is formed thinner than that in theotherportions, preferably, insulating film a range of 1,000˜5,000 Åthick. Of course, in this regard, the organic insulating film 75 aroundthe contact holes 72 and 76 for exposing the drain electrode 66 and theconductor pattern for the storage capacitor 64 may be formed with astep-shaped structure that its thickness is thinner than the otherportions.

In the meanwhile, a seal line is formed on one panel of them for thepurpose of attaching two panels for liquid crystal display and sealingthe liquid crystal material interposed therebetween, and since theadhesive strength of the seal line becomes weak on forming the seal lineon an organic insulating film 75, a poor contact is generated betweenthe two panels. It is preferable that, in order to prevent the poorcontact, the organic insulating film 75 is removed from an area wherethe seal line will be formed later, and that, for this, as shown in FIG.8 c, by forming a semi-transmittance area on the mask of the area wherethe seal line will be formed, the organic insulating film 75 is formedthinner than the other portions.

Here, a method for adjusting the thickness of a photosensitive film willbe described in detail later when a method for manufacturing a thin filmtransistor array panel for liquid crystal display using four masks isdescribe.

Next, as shown in FIG. 9, the passivation film 70 and the gateinsulating film 30 exposed by the contact holes 72, 74, 76 and 78 usingthe organic insulating film 75 as an etching mask are etched and so theconductor pattern for storage capacitor 64, the gate pattern 24, thedrain electrode 66 and the data pad 68 are exposed. Here, a method toetch the passivation film 70 is preferably a dry etching, and SF6⁺O₂ orCR4⁺O₂ is used as a dry etching gas. When the passivation film and thegate insulating film 30 are etched, as seen in drawings, they are etchedto lower side of the organic insulating film 75 to cause an under-cut,though using a dry etching.

Next, as shown in FIG. 10 a, an ashing process is performed to removepart of the organic insulating film 75, so that, in the pad portion, thepassivation layer 70 around the contact holes 74 and 78 is exposed byremoving the organic insulating film 75 having a small thickness, and inthe contact holes 72 and 76, the gate insulating film 30 and thepassivation film 70 are exposed by the organic insulating film 75. Thisenables the under-cut structure generated in the contact portion to beremoved. Here, as shown in FIG. 10 b, the passivation film 70 made ofSiNx is exposed in an area for forming the seal line. In this way, theseal line formed later can be formed on the passivation layer to improvethe adhesive strength between the two panels for liquid crystal display.

Finally, as previously shown in FIGS. 3 and 4, by depositing an ITO oran IZO and performing a patterning using a mask, the conductor patternfor storage capacitor 64 and the pixel electrode 82 connected to thedrain electrode 66 through the contact holes 72 and 76 are each formed,and also the assistant gate pad 84 and the assistant data pad 88 eachconnected to the gate pad 24 and the data pad 68 through the contactholes 74 and 78 are each formed. As described above, the under-cutstructure generated in the contact portion is removed by forming theorganic insulating film 75 around the contact holes 72, 74, 76 and 78thinner and performing an ahsing process, so that the pixel electrode82, the assistant gate pad 84 and the assistant data pad 88 can beprevented from being disconnected and the profile of them can be formedsmooth. Here, as seen in drawings, the assistant gate pad 84 and theassistant data pad 88 are formed to upper side of the passivation film70. When the assistant gate pad 84 or the assistant data pad 88 needs tocover lower metal pads 24 and 68 completely for the purpose ofpreventing the pads 24 and 68 from being corroded and is formed to theupper side of the passivation film 70, there are advantages of animprovement of the adhesive strength between the assistant pads 84 and88 and an enlargement of the assistant pads 84 and 88.

In the method for manufacturing the thin film transistor for liquidcrystal display according to the first embodiment, as described above,although the manufacturing method thereof described using five masks, itis equally applicable to a manufacturing method thereof using fourmasks. This will be described in detail with reference to drawings. Itwill be described that a method for manufacturing a semiconductor deviceaccording to a second embodiment, which uses an organic insulating filmnot as an interlayer insulating film but as a photosensitive filmpattern and adds a low dielectric CVD insulating film which has a lowdielectric constant less than 4.0 and is formed by a chemical vapordeposition, is applied.

First, referring to FIG. 11 to FIG. 13, a unit pixel structure of a thinfilm transistor array panel for liquid crystal display formed by usingfour masks according to an embodiment of the present invention will bedescribed in detail.

FIG. 11 is an arrangement view of a thin film transistor panel forliquid crystal display according to a second embodiment, and FIG. 12 andFIG. 13 are cross-sectional views taken along X II-X II′ and X III-XIII′ of the thin film transistor shown in FIG. 11.

Like the first embodiment, gate wire, which include gate lines 22 madeof conducting material with a low resistance such as, Al or Al alloy, orAg or Ag alloy, etc., gate pad 24 and gate electrode 26, are formed onan insulating substrate 10. The gate wire also include a storageelectrode 28 which is parallel with the gate lines 22 on the substrate10 and is applied with a voltage such as a common electrode voltageinputted to a common electrode placed in an upper plate from an externaldevice. The storage electrode 28 overlaps a conductor pattern forstorage capacitor 68 connected to a pixel electrode described later toform a storage capacitor for improving charge reservation ability of thepixel, and if a storage capacity generated by overlapping the pixelelectrode 82 described later with the gate line 22 is enough, thestorage capacitor may not be formed.

A gate insulating film 30 made of SiNx, etc., is formed on the gate wire22, 24, 26 and 28 to cover these.

Semiconductor patterns 42 and 48 made of a semiconductor such as ahydrogenated amorphous silicon is formed on the gate insulating film 30,and ohmic contact layer pattern or middle layer patterns 55, 56 and 58made of an amorphous silicon which n-type impurity such as P is dopedwith high concentration are formed on the semiconductor patterns 42 and48.

Data wire made of an aluminum-based conducting material with lowresistance are formed on the ohmic contact layer patterns 55, 56 and 58.The data wire include data line portion comprising data line 62, a datapad 68 connected to one end of the data line 62 to be applied with imagesignals from an external device, and a source electrode 65 of thin filmtransistor which is branch of the data line 62. The data wire alsoinclude a drain electrode 66 of thin film transistor separate from thedata line portion 62, 68 and 65 and placed opposite to the sourceelectrode 65 in relation to the gate electrode or charnel C, and aconductor pattern for storage capacitor 64 placed over the storageelectrode 28. In case the storage electrode is not formed, neither isthe conductor pattern formed.

The contact layer patterns 55, 56 and 58 play a part in reducing thecontact resistance between the semiconductor patterns 42 and 48 and thedata wire 62, 64, 65, 66 and 68 under themselves, and have perfectly thesame shapes as the data wire 62, 64, 65, 66 and 68. That is, the middlelayer pattern 55 in the data portion has the same shape as the dataportion 62, 65 and 68, the middle layer pattern for the drain electrode56 has the same shape as the drain electrode 66, and the middle layerpattern for the storage capacitor 58 has the same shape as the conductorpattern for the storage capacitor 68.

In the meantime, the semiconductor patterns 42 and 48 have the sameshapes as the data wire 62, 64, 65, 66 and 68 and the ohmic contactlayer patterns 55, 56 and 58 except the channel portion of the thin filmtransistor. In detail, the semiconductor pattern for storage capacitor48, the conductor pattern for storage capacitor 68 and the contact layerpattern for storage capacitor 58 have the same shapes, but thesemiconductor pattern for thin film transistor 42 has the slightlydifferent shape from the data wire and the contact layer patterns. Inother words, the data line portion 62, 68 and 65 in the channel portionof the thin film transistor, in particular, the source electrode 65 andthe drain electrode 66 are separate, and the middle layer 55 of the dataline portion and the contact layer pattern for drain electrode 56 arealso separate, however, the semiconductor pattern for thin filmtransistor 42 is not disconnected but connected in this place to form achannel of thin film transistor.

Unlike the first embodiment, on the data wire 62, 64, 65, 66 and 68, thepassivation film made of SiNx, and the low dielectric insulating film 73that has a low dielectric constant less than 4.0 and is formed by achemical vapor deposition, are formed, and these have the contact holes76, 78 and 72 for exposing the drain electrode 66, the data pad 68 andthe conductor pattern for storage capacitor 64, also have the contacthole 74 for exposing the gate insulating film 30 and the gate pad 24. Inthis regard, like the first embodiment, the low dielectric insulatingfilm 73 is removed from the pad portion to expose the passivation film70, and the borderline of the passivation film or the gate insulatingfilm as the lower insulating film is exposed in the contact holes 72 and76, and so the sidewalls of the contact holes 72 and 76 have thestep-shaped.

On the low dielectric insulating film 73, a pixel electrode 82, which isapplied with image signals from the thin film transistor to generate anelectric field in cooperation with electrodes in the upper plate, areformed. The pixel electrode 82 is made of a transparent conductingmaterial such as an IZO or an ITO, and is connected to the drainelectrode 66 via the contact hole 76 to receive the image signals. Thepixel electrode 82 also overlaps the adjacent gate line 22 and data line62 to increase the aperture rate, however, alternately not. In addition,the pixel electrode 82 is connected to the conductor pattern for storagecapacitor 64 via the contact hole 72 to transmit the image signalsthereto. On the gate pad 24 and the data pad 68, the assistant gate pad84 and the assistant data pad 88 connected thereto via the contact holes74 and 78 each. These play a part in complementing the adhesivity of thepads 24 and 68 and external circuit devices and protecting the pads,whether these are applied or not is selective.

As described above, also in the thin film transistor array panelaccording to the second embodiment, the sidewalls have step-shapedstructure by exposing the protecting film 70 as a lower insulating film,and since the passivation film 70 in the pad portion is exposed not togenerate a under-cut structure in the contact portion, the pixelelectrode 82, the assistant gate pad 84 and the assistant data pad 88can be prevented from being disconnected. Moreover, the assistant gatepad 84 and the assistant data pad 88 are formed to the upper side of thepassivation film 70.

Although the transparent ITO or IZO has been described as exemplarymaterials of the pixel electrode 82, opaque conducting materials may beused in case of reflective liquid crystal displays.

A method for manufacturing a thin film transistor for liquid crystaldisplay having structures of FIG. 11 to FIG. 13 using four masks will bedescribed in detail with reference to FIG. 11 to FIG. 13 and FIG. 14 ato FIG. 20 c.

First, as shown in FIGS. 14 a to 14 c, in the same manner as the firstembodiment, a conducting material for gate wire is deposited, and thenthe gate wire including a gate line 22, a gate pad 24, a gate electrode26 and a storage electrode 28 are formed on a substrate 10 by a photoetching process using a first mask.

Next, as shown in FIGS. 15 a and 15 b, a gate insulating film 30, asemiconductor layer 40 and a middle layer 50 are deposited in succession1,500 Å-5,000 Å, 500 Å-2,000 Å and 300 Å-600 Å thick, respectively, andthen, a conductor layer 60 made of a conducting material for data wirewith a low resistance is deposited 1,500 Å-3,000 Å thick by way of asputtering, etc., and thereafter, a photosensitive film 110 is coated 1μm-2 μm thick thereon.

Then, after a light is irradiated to the photosensitive film 110 througha second mask and developed, the photosensitive patterns 112 and 114 areformed as shown in FIGS. 16 b and 16 c. The channel portion C of thinfilm transistor of the photosensitive film patterns 112 and 114, i.e.,the first portion 114 posed between the source electrode 65 and thedrain electrode 66 is made to be thinner than the data wire portion A,i.e., the second portion 112 posed in the portion where the data wire62, 64, 66 and 68 will be formed, and all the photosensitive films inthe other portions are removed. Here, the ratio of the thickness of thephotosensitive film 114 left in the channel portion C and that of thephotosensitive film 112 left in the data wire portion A are made to bevaried depending on a process condition of etching process describedlater, and it is preferable that the thickness of the first portion 114is less than a half, for example, less than 4,000 Å of that of thesecond portion 112.

As above, there may be several methods for varying the thickness of thephotosensitive film depending on positions, and the pattern of a slittype or a lattice type is formed on the mask, or, the semi-transmittancearea is formed thereon by using a semi-transparent film, in order toadjust an amount of a light transmittance in an area A. Of course, thismethod is equally applicable to the case that the organic insulatingfilm (75, see FIG. 7) around the contact holes 72, 74, 76 and 78 isformed thinner than that in the other portions, and it is preferablethat its thickness is adjusted in consideration of an ashing process.

In this regard, it is preferable that a line width of the patterns or aninterval of the pattern placed among the slits, that is, the width ofthe slit is smaller than a resolution used at exposure, in case of usinga semi-transparent film, thin films with different transmittances ordifferent thickness may be used to adjust the transmittance onmanufacturing masks.

When a light is irradiated to the photosensitive film through suchmasks, high molecules in the portion exposed directly to the light arecompletely decomposed, and high molecules in the portion where the slitpattern or the semi-transparent film is formed are not completelydecomposed because an amount of a light irradiation is smaller, and highmolecules in the portion blocked by a light-shield film is hardlydecomposed. Next, when the photosensitive film is developed, the portionwhere the high molecules are not decomposed is left, and the portionwhere the light is irradiated a little is left thinner than that in theportion where the light is not irradiated at all. Here, since themolecules all are decomposed in case exposure time is made to be long,it is necessary not to do so.

A photosensitive film made of a material capable of reflowing is usedand exposed with a mask whose portions transmitting a light completelyand not transmitting a light completely is divided, and then, developedand reflowed to make part of the photosensitive film flow to the portionwhere the photosensitive film does not remain, and consequently, suchthinner photosensitive film 114 may be formed.

Next, the photosensitive film 114 and the lower films thereof, i.e., theconductor layer 60, the middle layer 50 and the semiconductor layer 40are etched. In this case, the data wire and the lower films thereof haveto be left the same in the data wire portion A, only the semiconductorlayer has to be left in the channel portion C, and the above threelayers 60, 50 and 40 all have to be removed to expose the gateinsulating film 30 in the other portions B.

First, as shown in FIGS. 17 a and 17 b, the conductor layer 60 exposedin the other portions B is removed to expose the middle layer 50thereof. Both a dry etching and a wet etching are used in this process,and here, they are preferably performed under the condition that theconductor layer 60 is etched and the photosensitive film patterns 112and 114 are hardly etched. However, it is not easy that the condition,which only the conductor layer 60 is etched and the photosensitive filmpatterns 112 and 114 is not etched, is found in the dry etching, andtherefore it may be performed under the condition that thephotosensitive patterns 112 and 114 are etched, too. In this case, thefirst portion 114 is made to be thicker than in the wet etching, andhence it has to be prevented that the first portion 114 is so removedthat the lower conductor layer 60 is exposed.

Here, in case that the conducting material for data wire is Al or Alalloy, either will do of the dry etching and the wet etching. However,in case of Cr, since the first portion 114 is not removed well, the wetetching had better be used, and CeNHO₃ is used as an etchant, and alsothe dry etching may be used when Cr is deposited very thinly to anextent of 500 Å thick.

In this way, as shown in FIG. 17 a and FIG. 17 b, the conductor layer 60in the channel portion C and the data wire B, that is, only theconductor pattern for source/drain 67 and the conductor pattern forstorage capacitor 64 are left and the conductor pattern 60 in the otherportions B are removed to expose the middle layer 50 thereof. Here, theremaining conductor patterns 67 and 64 are the same forms as the datawire 62, 64, 65, 66 and 68 except the point that the source electrode 65and the drain electrode 66 are not disconnected but connected.Furthermore, when the dry etching is used, the photosensitive patterns112 and 114 are etched to some extent of thickness.

Next, as shown in FIG. 18 a and FIG. 18 b, the exposed middle layer 50and the lower semiconductor layer 40 thereof in the other portions B aresimultaneously removed with the first portion by a dry etching. When theconductor pattern 67 is etched by a dry etching, the middle layer 50 andthe semiconductor layer 40 are sequentially etched by a dry etching,which is proceeded with an in-situ. The etching of the middle layer 50and the semiconductor layer 40 should be performed under the conditionthat the photosensitive film patterns 112 and 114, the middle layer 50and the semiconductor layer 40 (the middle layer and the semiconductorlayer hardly have etching selectivity) are simultaneously etched and thegate insulating film 30 is not etched, especially it is preferable thatthe etching ratio of the photosensitive film patterns 112 and 114 andthe semiconductor pattern 40 is almost the same condition. When theratio of the photosensitive film patterns 112 and 114 and thesemiconductor pattern 40 is the same, the thickness of the first portion114 is the same as, or less than the sum of that of the semiconductorlayer 40 and the middle layer 50.

In this way, as shown in FIGS. 18 a and 18 b, the conductor layers inthe channel portion C and the data wire B, that is, only the conductorpattern for source/drain 67 and the conductor pattern for storagecapacitor 64 is left and the conductor layers 60 in the other portions Ball are removed. Furthermore, the first portion 114 in the channelportion C is removed to expose the conductor pattern for source/drain,and the middle layer 50 and the semiconductor layers 40 in the otherportions B are removed to expose the lower gate insulating film 30thereof. In the meanwhile, the second portion 112 in the data wire A isalso etched, and hence it becomes thinner. Moreover, the conductorpatterns 42 and 48 are completed in this procedure.

The reference numerals 57 and 58 indicate the lower middle layer patternof the conductor pattern for source/drain 67 and the lower middle layerpattern of the conductor pattern for storage capacitor 64, respectively.Here, the conductor pattern for source/drain in the channel portion Cmay be exposed by a separate PR etch back process, and, under thecondition that a photosensitive film is etched sufficiently, the PR etchback process may be omitted.

Then, photosensitive film remnants left in the surface of the conductorpattern for source/drain in the channel portion C are removed through anashing process.

Next, as shown in FIGS. 19 a and 19 b, the conductor pattern forsource/drain 67 and the lower middle pattern for source/drain 57 thereofin the channel portion C are etched to be removed. Here, the etching ofboth of them may be done using only a dry etching, the conductor patternfor source/drain is etched by a wet etching, and the middle layerpattern 57 is etched by a dry etching. In this regard, as shown in FIG.15, part of the semiconductor pattern 42 is removed and thus itsthickness becomes smaller, and here, the second portion 112 of thephotosensitive film pattern is also etched to some extent of thickness.This etching is performed under the condition that the gate insulatingfilm 30 is not etched, and it is preferable that the photosensitive filmpattern is thick so that the second portion 12 is etched not to exposethe lower data wire 62, 64, 65, 66 and 68 thereof.

In this way, while the source electrode 65 and the drain electrode 66are isolated, the data wire 62, 64, 65, 66 and 68 and the contact layerpatterns 55, 56 and 58 thereof are completed.

Finally, the second portion 112 of the photosensitive film left in thedata wiring portion A is removed. However, the second portion 112 may beremoved after the conductor pattern 67 for source/drain in the channelportion C is removed and before the lower middle layer pattern 57thereof is removed.

After the data wire 62, 64, 65, 66 and 68 are formed in such way, asshown in FIG. 20 a to FIG. 20 c, SiNx is deposited by a chemical vapordeposition to form the passivation layer 70, and SiOC or SiOF with a lowdielectric constant which is less than 4.0 is deposited thereon by achemical vapor deposition to form the low dielectric insulating film 73.Next, after an organic insulating film is formed on the low dielectricinsulating film 73 by a spin coating, it is exposed and developed usinga third mask to form the photosensitive pattern 250, and, by using thisas an etching mask, the contact holes 72, 74, 76 and 78 for exposing theconductor pattern for storage capacitor 64, the gate pad 24, the drainelectrode 66 and the data pad 68 are formed. Also in this regard, thepassivation film 70 and the gate insulating film 30 are etched to thelower side of the low dielectric insulating film 73 to generate anunder-cut in the contact portion, and as in the method for manufacturingthe semiconductor device according to the second embodiment, in order toremove this, the photosensitive film pattern 250 in the pad portionaround the contact holes 74 and 78 at least is formed thinner than thatin the other portions. Of course, the photosensitive film pattern may beformed a step-shaped so that the thickness around the contact holes 72and 74 also become thinner by forming slit patterns on the mask.

Next, as shown in FIGS. 21 a and b, a thin photosensitive film formedaround the contact holes 74 and 78 is removed by performing an ashingprocess to remove some thickness of the photosensitive film, andthereafter, a low dielectric insulating film 73, which is exposed usingthe photosensitive pattern 250 as an etching mask, is etched. Then, asshown in FIGS. 21 a and b, the passivation film 70 is exposed in the padportion. In the ashing process, part of the photosensitive film over thecontact holes 72 and 76 is removed to expose the borderline of the lowdielectric insulating film 73 defining the contact holes 72 and 76. Ifthe low dielectric insulating film 73 is etched using the photosensitivepattern as an etching mask, the under-cut structure is removed on thesidewalls of the contact holes 72 and 76, as shown in figures. Here, itis preferable to use a dry etching, and the etching condition having anetching selectivity between the passivation film 70 and the lowdielectric insulating film 73 should be applied. A gas mixed afluorine-substituted-gas such as SF₆ ⁺O₂, CR₄ ⁺O₂ or C₂F₆ ⁺O₂ withoxygen may be used as an etching gas and its composition ratio isvariable depending on the forming condition of the low dielectricinsulating film 73.

Finally, after the photosensitive film pattern is removed, as shown inFIGS. 11 to 13, ITO or IZO having the thickness of 400 Å to 500 Å isdeposited, and etched using the fourth mask to form a pixel electrode 82connected to the conductor pattern for storage capacitor pattern 64, anassistant gate pad 84 connected the gate pad 24 and an assistant datapad 88 connected to the data pad 68.

The second embodiment of this present invention not only has the effectaccording to the first embodiment but also can make the manufacturingprocess simplified by forming the data wire 62, 64, 65, 66 and 68, thelower contact layer pattern 55, 56 and 58 thereof and the semiconductorpattern 42 and 48 using one mask and by isolating the source electrode65 and the drain electrode 66 in this process. Of course, also in themethod for manufacturing the thin film transistor panel for liquidcrystal display according to the second embodiment, a photosensitivefilm pattern is formed thin on a portion where a seal line will beformed and the low dielectric insulating film 73 in the portion isremoved to expose the passivation film 70.

In the thin film transistor panel for liquid crystal displaymanufactured through such manufacturing process, as described above, apad portion and a driving integrated circuit may be electricallyconnected by a TCP or COF manner which the driving integrated circuit ispacked on a film, or by a COG manner which a driving integrated circuitis directly mounted on a substrate.

As above, according to the present invention, by forming thephotosensitive film around the contact holes thinner than the otherportions on under-cutting the lower film in the contact portion, then,performing an ashing to expose the border of the lower insulating filmin the contact portion, and hence forming the sidewall of the contacthole as a step-shaped, the under-cut can be removed in the contactportion. Through this, the display feature can be improved by preventinga disconnection generated in the contact portion to secure reliabilitythereof, and the manufacturing process cab be simplified and themanufacturing cost can be reduced by minimizing the photo etchingprocess to manufacture the thin film transistor for liquid crystaldisplay. Furthermore, the poor contact between two panels for liquidcrystal display can be improved by removing the organic film in theportion where the seal line will be formed.

1. A method for manufacturing a semiconductor device comprising: formingfirst wire on a substrate; forming a lower film on the first wire;forming a photosensitive pattern on the lower film using aphotosensitive material; forming contact holes for exposing the firstwire by etching the lower film using the photosensitive film as anetching mask; removing part of the photosensitive film pattern by anashing process to expose a borderline of the lower film defining thecontact holes; and forming second wire connected to the first wire viathe contact holes.
 2. The method of claim 1, wherein the lower film isformed of an insulating film made of SiNx or SiOx.
 3. The method ofclaim 1, wherein the lower film is formed of a conducting film.
 4. Themethod of claim 1, comprising: forming the lower film of a firstinsulating film and a second insulating film; exposing the borderline ofthe lower film; and thereafter, etching the second insulating film notblocked by the photosensitive film pattern to expose the borderline ofthe first insulating film in the contact holes.
 5. The method of claim1, wherein the photosensitive film pattern around the contact holes isformed thinner than that in the other portions.
 6. A method formanufacturing a thin film transistor array panel for liquid crystaldisplay comprising: forming gate wire including a gate line, a gateelectrode connected to the gate line, and a gate pad connected to oneend of the gate line; depositing a gate insulating film; forming asemiconductor layer; forming data wire including a data line crossingwith the gate line, a source electrode connected to the data electrodeand adjacent to the gate electrode, a drain electrode placed opposite tothe source electrode in relation to the gate electrode, and a data padconnected to one end of the date line; depositing an insulating film;forming a photosensitive organic insulating film pattern on theinsulating film; etching the insulating film using the organicinsulating film pattern as an etching mask to expose first contact holesfor exposing the gate pad or the data pad; performing an ashing processto expose borderline of the insulating film in the contact holes; andforming an assistant pad connected to the gate pad or the data pad viathe first contact holes.
 7. The method of claim 6, wherein the organicinsulating film pattern around the contact holes is formed thinner thanthat in the other portions.
 8. The method of claim 7, furthercomprising: forming the insulating film of a first insulating film and asecond insulating film; exposing the borderline of the insulating film;thereafter, etching the second insulating film not blocked by theorganic insulating pattern; and removing the organic insulating pattern.9. The method of claim 8, wherein the second insulating film is a lowdielectric insulating film which has a low dielectric constant less than4.0 and is formed by a chemical vapor deposition.
 10. The method ofclaim 6, wherein the organic insulating film pattern has second contactholes for exposing the drain electrode with the insulating film, furthercomprising forming a pixel electrode electrically connected to the drainelectrode via the second contact holes on the same layer as theassistant pad.
 11. The method of claim 10, wherein the second contactholes are formed with the first contact holes, and the organicinsulating pattern around the contact holes is formed thinner than thatin the other portions.
 12. The method of claim 6, wherein the thin filmtransistor array panel for liquid crystal display has a portion where aseal line for sealing a liquid crystal material is formed, furthercomprising: forming the organic insulating film pattern at the portionthinner than that at the other portions; and removing the organicinsulating film pattern at the portion by the ashing process.
 13. Themethod of claim 6, wherein both the data wire and the semiconductorlayer are formed by a photo etching process using photosensitivepatterns whose thickness is partly different.